The present invention is directed to a gas laser wherein a housing tube is provided having end pieces at ends thereof with mounts for optical elements. .A capillary is provided which projects into the housing tube. A cylindrical cathode surrounds an end of the capillary. Such a gas laser is disclosed by U.S. Pat. No. 4,311,969, incorporated herein by reference. There, a termination that is carried at and fixed to a face plate of metal is applied to a cathode. For example, a nose that proceeds through a beam passage opening is applied to the electrode and this nose is plugged into the end plate and is riveted thereto in the fashion of a tube rivet. In this known embodiment, there is the risk that the heating required in the vacuum-tight closing of the housing leads to the deformation of the nose since the cathodes of lasers are usually formed of aluminum or of aluminum alloys, and the cathode nose is loosened as a result thereof. Thus, the electrical contact that is to be guaranteed via the same connection is interrupted at times, that is it can become an intermittent contact. This cathode fastening is fundamentally unsuited for manufacture in glass solder technology wherein an entire batch of tubes is simultaneously soldered in a furnace. The cathode already becomes soft at the temperature needed for the glass soldering; the fastening becomes unstable during the soldering (difference in expansion); the contacting is no longer faultlessly guaranteed; and the position in the housing tube is no longer faultlessly defined, so that a mechanical chattering during later operation must be feared. In an additional fastening of the electrode conforming to the above mentioned U.S. patent, a spring is provided at the open end of the cathode, this spring having spring arms pressing against the enveloping tube and against the capillary. A relatively high spring power must be exerted so that the spring is held in its axial position solely on the basis of the spring power. Furthermore, the spring power must suffice for centering the capillary that is generally formed of glass or of ceramic; and it must intercept mechanical vibrations of the capillary. For these reasons, the electrode must be shifted into its ultimate position before the housing is closed. This causes individual handling of the tubes; and a batch soldering is fundamentally impossible without further work in such a design.